Three-Dimensional Porous Scaffolds with Biomimetic Microarchitecture and Bioactivity for Cartilage Tissue Engineering

Ideal tissue-engineering cartilage scaffolds should possess the same nanofibrous structure as the microstructure of native cartilage as well as the same biological function provided by the microenvironment for neocartilage regeneration. In the present study, three-dimensional composite biomimetic scaffolds with different concentration ratios of electrospun gelatin-polycaprolactone (gelatin-PCL) nanofibers and decellularized cartilage extracellular matrix (DCECM) were fabricated. The nanofibers with the biomimetic microarchitecture of native cartilage served as a skeleton with excellent mechanical properties, and the DCECM served as a biological functionalization platform for the induction of cell response and the promotion of cartilage regeneration. Experimental results showed that the composite nanofiber/DCECM (NF/DCECM) scaffolds had stronger mechanical properties and structural stability in wet state compared with those of DCECM scaffolds. In vitro experiments demonstrated that all scaffolds had good biocompatibility, but the chondrocyte proliferation rate of the composite NF/DCECM scaffolds was higher than that of the NF scaffolds. In vitro and in vivo cartilage regeneration results indicated that the DCECM component of the composite scaffolds facilitated early maturation of the cartilage lacuna and the secretion of collagen and glycosaminoglycan. The macroscopic and histological results at 12 weeks postsurgery exhibited that the composite NF/DCECM scaffolds yielded better cartilage repair outcomes than those of the nontreated group and NF scaffolds group. Overall, the present study demonstrated that the structurally and functionally biomimetic NF/DCECM scaffold is a promising tissue engineering scaffold for cartilage regeneration and cartilage defect repair.